NOTE: This description was
published in December, 1974. Revised statistics currently being
used, which became available after publishing, are noted in parenthetical
statements.

Natural Disaster Survey Report 74-1

The Widespread Tornado Outbreak
of April 3-4, 1974

A Report to the Administrator

Description of the Outbreak

In terms of total number, path
length, and total damage, the massive tornado occurrence of April
3-4, 1974, was more extensive than all previously known outbreaks.
Of the 127 tornadoes so far documented (148 tornadoes according
to revised statistics by T. Theodore Fujita, The University of
Chicago), 118 had paths over a mile long. The total paths amounted
to 2,014 miles (2,500 miles according to revised statistics by
Mr. Fujita), resulting in 335 deaths (330 deaths according to
revised statistics by Mr. Fujita). By comparison, during the
tri-State out-break of March 18, 1925, seven tornadoes traveled
437 miles and caused 746 deaths. The Palm Sunday outbreak of
April 11, 1965, spawned 31 tornadoes, which had paths totaling
853 miles, and killed 256.

The year 1973 went down in
history as the year of the tornado. More than 1,100 tornadoes
were reported--an all-time high. The first quarter of 1974 was
just as busy, but severe weather forecasts generally were confined
to a few watch areas on each storm day. This pattern was broken
on Monday, April 1, when 11 severe weather watch areas were issued
and more than 20 tornadoes developed from Alabama and Mississippi
through the central States into Indiana and Ohio. Three deaths
and much property damage were attributed to tornadoes. The storms
of April 1 served to alert the forecasters to the potential for
widespread outbreaks, and the impact of these storms was fresh
in the minds of many people when they heard the watches and warnings
of April 3. In Alabama and Tennessee, where severe damage occurred
on both days, many lives were saved during the April 3-4 disaster
because the public took protective actions that might not otherwise
have been taken had it not been for the April I storms.

On Tuesday morning, April 2,
the forecasters at the NSSFC determined that the developing storm
system had the potential to produce severe thunderstorms the
following day, although the precise location and timing Of Such
activity was not yet evident. At that time, it appeared that
the severe activity would occur somewhere in the middle or lower
Mississippi Valley. Consequently, the Kansas City RWCC suggested
in a teletypewriter message to 10 Central Region network radar
stations that any needed maintenance be done by April 2. (Stations
alerted were Garden City and Wichita, Kans.; Grand Island, Neb.;
St. Louis and Monett, Mo.; Detroit, Mich.; Des Moines, Iowa;
Minneapolis, Minn.; Marseilles, Ill.; and Evansville, Ind.) Meanwhile,
the Fort Worth RWCC was phoning to advise several Southern Region
WSFOs of the coming severe weather potential and the need for
radar maintenance. (Offices contacted were WSFOs in Oklahoma
City, Little Rock, Memphis, Birmingham, and Jackson.)

While this preliminary alert
did not extend far enough east to include all the tornadoes that
occurred, and did include a large area in the central and southern
plains in which severe thunderstorms did not occur, it gave many
NOAA offices over 24 hours in which to prepare for the outbreak.

Through the night on Tuesday,
indications of the storms to come were accumulating but the tremendous
magnitude and intensity of what was actually to occur, as well
as the precise timing and location of the storms, were still
not evident. Two severe weather watches were issued during the
predawn hours on Wednesday, April 3, for portions of the lower
Mississippi Valley, but little activity was noted in these areas.
The pace increased in the NSSFC and field offices during the
forenoon, as thunderstorms began to build. Severe Thunderstorm
Watch No. 92 covering portions of the Ohio Valley was issued
at 8:27 a.m. CDT. From that time until 3:00 a.m. CDT the next
morning, NSSFC issued 28 Severe Weather Watches covering almost
the entire area from the Gulf of Mexico to the Canadian border
and from the, Mississippi River to the East Coast. During this
period, National Weather Service Offices issued about 150 tornado
warnings. The major activity occurred between 2:00 p.m. and 10:00
p.m. on April 3. In all, 13 States had tornadoes.

The rapid development and widespread
extent of the tornado outbreak are evident in the reported times
of the first tornado in the seven States struck during the afternoon
hours of April 3. Around 2:00 p.m. CDT, tornadoes touched down
in Bradley County, Tenn., and Gilmer County, Ga. Within 10 minutes,
tornadoes were reported in McLean and Logan Counties, Ill. At
2:20 p.m. CDT, separate killer storms set down in the Indiana
counties of Perry and Lawrence. In Ohio the first tornado was
reported about 3:30 p.m. CDT, and the Brandenburg, Ky., storm
touched down at 3:40 p.m. Alabama's first tornado followed by
less than an hour, striking 8 miles west of Birmingham at 4:30
p.m. CDT.

For comparative purposes, for
all the tornadoes reported during this outbreak, the mean path
length was on the order of 18.7 miles whereas the mean path length
for all tornadoes in 1973 was 4.7 miles. For all tornadoes in
1972 it was 3.3 miles. In a rating of intensity of tornadoes
on a scale from F0 to F5, six tornadoes in this outbreak had
an intensity of F5. In 1973, only one tornado had an intensity
of F5. In 1972, no tornadoes reached this intensity. In 1971,
two tornadoes had an intensity of F5.

Of the casualties and losses
suffered in the 13 States surveyed by the American Red Cross,
some were caused by straight-line winds rather than tornadic-storms,
particularly those involving mobile homes. Some of the deaths
reported by the Red Cross were caused by heart attacks and not
by direct storm injury. Large hail during the severe thunderstorms
and tornadoes contributed to the total damage. The States of
Alabama, Georgia, Tennessee, Kentucky, Indiana, and Ohio were
the region of greatest storm activity and damage. Detailed descriptions
of tornado activity in each State are provided in the sections
that follow. The extremely large number of storms that occurred,
and their rapid movement, magnified the problems involved in
determining the number and sequence of events. Detailed studies
of individual storms and further analyses may modify the descriptions
given in this report.

*Numbers assigned to the tornadoes
correspond to those given on the University of Chicago map furnished
with this report.